Biometric detection module and biometric detection device with denoising function

ABSTRACT

A biometric detection module including a light source module, a detection region and a control module is provided. The light source module is configured to emit green light, red light and IR light in a time division manner to illuminate a skin surface. The detection region is configured to detect penetration light emitted from the light source module for illuminating the skin surface and passing through body tissues to correspondingly generate a green light signal, a red light signal and an IR light signal. The control module is configured to determine a filtering parameter according to the green light signal to accordingly filter the red light signal and the IR light signal, and calculate a biometric characteristic according to at least one of the green light signal, a filtered red light signal and a filtered IR light signal.

RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 14/685,782 filed on, Apr. 14, 2015, which is basedon and claims priority to Taiwanese Application Number 103123543, filedJul. 8, 2014, the disclosure of which is hereby incorporated byreference herein in its entirety.

BACKGROUND 1. Field of the Disclosure

This disclosure generally relates to a biometric detection module and,more particularly, to a biometric detection module with denoisingfunction.

2. Description of the Related Art

Conventional pulse oximeters utilize a noninvasive method to monitor theblood oxygenation and the heart rate of a user. A pulse oximetergenerally emits a red light beam (wavelength of about 660 nm) and aninfrared light beam (wavelength of about 910 nm) to penetrate a part ofthe human body and detects an intensity variation of the penetratinglight based on the feature that the oxyhemoglobin and thedeoxyhemoglobin have different absorptivities in particular spectrum,e.g. referring to U.S. Pat. No. 7,072,701 entitled “Method forspectrophotometric blood oxygenation monitoring”. After the intensityvariations, e.g. photoplethysmographic signals or PPG signals, of thepenetrating light of the two wavelengths are detected, the bloodoxygenation can then be calculated according to an equation: Bloodoxygenation=100%×[HbO₂]/([HbO₂]+[Hb]), wherein [HbO₂] is anoxyhemoglobin concentration; and [Hb] is a deoxyhemoglobinconcentration.

Generally, the intensity variations of the penetrating light of the twowavelengths detected by a pulse oximeter will increase and decrease withheartbeats. This is because blood vessels expand and contract with theheartbeats such that the blood volume that the light beams pass throughwill change to accordingly change the ratio of light energy beingabsorbed. Therefore, the absorptivity of blood of different lightspectra can be calculated according to the intensity informationchanging continuously so as to calculate the physiology information,e.g. the oxyhemoglobin and deoxyhemoglobin concentrations, respectively.Finally, the blood oxygenation can be calculated according to the aboveequation.

However, as the pulse oximeter detects the intensity variation of thepenetrating light passing through body tissues, different intensitysignals will be detected by detecting different parts of the human body.In addition, when the part of the human body being detected has arelative movement with respect to the pulse oximeter, a disturbed signalcan be detected such that it is not possible to calculate correctphysiology information. Therefore, a clear PPG signal is difficult to bedetected under a condition of a non-static state.

SUMMARY

Accordingly, the present disclosure provides a biometric detectiondevice adaptable to non-static detecting states.

The present disclosure provides a biometric detection device configuredto detect at least one biometric characteristic from a skin region in aconcha. The biometric detection device includes a biometric detectionmodule having a detection unit and an earphone having a processor. Thedetection unit includes a light source module, a detection region and anabrasion-proof layer. The light source module is configured to emitgreen light, red light and infrared light in a time division manner toilluminate the skin region. The detection region is configured to detectpenetrating light emitted from the light source module for illuminatingthe skin region and passing through body tissues to correspondinglygenerate a green light signal, a red light signal and an infrared lightsignal. The abrasion-proof layer covers the detection region and has anupper surface as a detection surface, wherein a thickness of theabrasion-proof layer is smaller than 100 micrometers, and the uppersurface is configured to be in contact with the skin region whendetecting the biometric characteristic such that the light emitted fromthe light source module illuminates the skin region and sequentiallypasses through the body tissues and the abrasion-proof layer to bedetected by the detection region. The processor of the earphone isconfigured to convert the green light signal to frequency domain todetermine a filtering parameter according to a frequency domain greenlight signal, respectively convert the red light signal and the infraredlight signal to a frequency domain red light signal and a frequencydomain infrared light signal, filter the frequency domain red lightsignal and the frequency domain infrared light signal using thefiltering parameter determined from the frequency domain green lightsignal, to obtain a filtered red light signal and a filtered infraredlight signal, and calculate the biometric characteristic according to atleast one of the green light signal, the filtered red light signal andthe filtered infrared light signal.

The present disclosure further provides a biometric detection moduleconfigured to detect at least one biometric characteristic from a skinregion. The biometric detection module includes a light source module, adetection unit, a control module and an abrasion-proof layer. The lightsource module is configured to emit green light, red light and infraredlight in a time division manner to illuminate the skin region. Thedetection region is configured to detect penetrating light emitted fromthe light source module for illuminating the skin region and passingthrough body tissues to correspondingly generate a green light signal, ared light signal and an infrared light signal. The control module isconfigured to control the light source module to emit light, determine afiltering parameter according to the green light signal to accordinglyfilter the red light signal and the infrared light signal, and calculatethe biometric characteristic according to at least one of the greenlight signal, the filtered red light signal and the filtered infraredlight signal. The abrasion-proof layer covers the detection region andhas an upper surface as a detection surface, wherein a thickness of theabrasion-proof layer is smaller than 100 micrometers, and the uppersurface is configured to be in contact with the skin region whendetecting the biometric characteristic such that the light emitted fromthe light source module illuminates the skin region and sequentiallypasses through the body tissues and the abrasion-proof layer to bedetected by the detection region.

The present disclosure further provides a biometric detection deviceconfigured to detect at least one biometric characteristic from a skinregion. The biometric detection device includes a biometric detectionmodule and a device having a processor. The biometric detection moduleincludes a light source module, a detection region and an abrasion-prooflayer. The light source module is configured to emit green light, redlight and infrared light in a time division manner to illuminate theskin region. The detection region is configured to detect penetratinglight emitted from the light source module for illuminating the skinregion and passing through body tissues to correspondingly generate agreen light signal, a red light signal and an infrared light signal. Theabrasion-proof layer covers the detection region and has an uppersurface as a detection surface, wherein a thickness of theabrasion-proof layer is smaller than 100 micrometers, and the uppersurface is configured to be in contact with the skin region whendetecting the biometric characteristic such that the light emitted fromthe light source module illuminates the skin region and sequentiallypasses through the body tissues and the abrasion-proof layer to bedetected by the detection region. The biometric detection module isattached to the device, and the processor is configured to determine afiltering parameter according to the green light signal to accordinglyfilter the red light signal and the infrared light signal, and calculatethe biometric characteristic according to at least one of the greenlight signal, the filtered red light signal and the filtered infraredlight signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages, and novel features of the present disclosurewill become more apparent from the following detailed description whentaken in conjunction with the accompanying drawings.

FIG. 1A is a block diagram of a biometric detection module according toone embodiment of the present disclosure.

FIG. 1B is an operational schematic diagram of a biometric detectionmodule according to one embodiment of the present disclosure.

FIGS. 2A and 2B are detected signals of a biometric detection module infrequency domain according to some embodiments of the presentdisclosure.

FIGS. 3A and 3B are schematic diagrams of a biometric detection moduleapplied to glasses according to some embodiments of the presentdisclosure.

FIG. 4 is a schematic diagram of wearing the glasses to which abiometric detection module of some embodiments of the present disclosureis applied.

FIG. 5 is a schematic diagram of a biometric detection module applied toan earphone according to one embodiment of the present disclosure.

FIG. 6 is a schematic diagram of a thin biometric detection moduleaccording to one embodiment of the present disclosure.

FIG. 7 is an upper view of the detection region of a biometric detectionmodule according to one embodiment of the present disclosure.

FIGS. 8A and 8B are upper views of a biometric detection moduleaccording to some embodiments of the present disclosure.

FIGS. 9A and 9B are cross-sectional views of the thin semiconductorstructure of a biometric detection module according to some embodimentsof the present disclosure.

FIG. 10 is a flow chart of a biometric detection method of a biometricdetection module according to one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENT

It should be noted that, wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

The present disclosure provides a biometric detection device adaptableto head accessories and may be attached to glasses or earphone devices,but not limited thereto. The biometric detection device has the functionof removing noises caused by the movement. The biometric detectiondevice of the present disclosure may also be attached to other headgearsusing a securing member, e.g. attaching and detaching from a hat or acap through a clamp such that it may be mounted while being used so asto improve the practicality thereof.

Referring to FIG. 1A, it is a block diagram of a biometric detectionmodule according to one embodiment of the present disclosure. Thebiometric detection module includes a light source module 101, adetection region 103A, a control module 106, an indication unit 108 anda power module 109. The light source module 101, the detection region103A and the control module 106 may form a detection unit 10 fordetecting at least one biometric characteristic, e.g., a heart rate, ablood oxygenation and/or a second derivative of photoplethysmogram, froma skin surface S via a detection surface Sd thereof, wherein theprinciple of detecting the heart rate, the blood oxygenation and thesecond derivative of photoplethysmogram according to PPG signals isknown to the art and thus details thereof are not described herein. Theindication unit 108 is configured to show the biometric characteristicthrough audio or images, e.g. including a speaker module or a displaydevice. The power module 109 is configured to provide power required bythe detection unit 10 in operation. It should be mentioned that when thebiometric detection module 1 is attached to a head-mounted device(illustrated with examples below), the indication unit 108 and the powermodule 109 may be shared with the head-mounted device but not includedin the biometric detection module 1 as long as they are electricallyconnected to the biometric detection module 1 for signal transmission.

The light source module 101 includes, for example, at least one lightemitting diode, at least one laser diode, at least one organic lightemitting diode or other active light sources configured to emit greenlight, red light and infrared light in a time division manner toilluminate the skin surface S. In one embodiment, the light sourcemodule 101 includes a single light source whose emission spectrum ischangeable by adjusting a driving parameter (such as the driving currentor the driving voltage) so as to emit green light, red light andinfrared light, wherein a wavelength of the green light is between, forexample, 490 nm and 570 nm, and the red light and the infrared light arethose generally used in the biometric detection. In another embodiment,the light source module 101 includes a green light source, a red lightsource and an infrared light source configured to emit green light, redlight and infrared light, respectively.

The detection region 103A is, for example, a semiconductor detectionregion which includes a plurality of detection pixels each including atleast one photodiode configured to convert optical energy to electricsignals. The detection region 103A is configured to detect penetratinglight emitted from the light source module 101 for illuminating the skinsurface S and passing through body tissues so as to correspondinglygenerate a green light signal, a red light signal and an infrared lightsignal, wherein the green light signal, the red light signal and theinfrared light signal are referred to photoplethysmographic signals orPPG signals.

The control module 106 is configured to control the light source module101 to emit light in a time division manner and corresponding to thelight detection of the detection region 103A, as shown in FIG. 1B,wherein the signal sequence shown in FIG. 1B is only intended toillustrate but not to limit the present disclosure. When the biometricdetection module 1 is adapted to a head accessory, a relative positionbetween the biometric detection module 1 and the skin surface S may notbe stable such that noises are generated in the detected signals (i.e.the PPG signals). Accordingly, in the present disclosure the green lightsignal is used to determine a filtering parameter configured to filterthe red light signal and the infrared light signal.

For example, referring to FIG. 2A, it is a schematic diagram of thepower spectral density (PSD) in frequency domain converted from the redlight signal or the infrared light signal detected by the biometricdetection module 1, wherein a main frequency in the frequency domainsignals being detected is not obvious due to the noises. Referring toFIG. 2B, it is a schematic diagram of the power spectral density (PSD)in frequency domain converted from the green light signal detected bythe biometric detection module 1. As SPO₂ has a higher absorption of thegreen light, the filtering parameter is determined according to afrequency domain green light signal (as FIG. 2B), e.g. the signalcomponent at 1 Hz being served as a basic frequency herein, wherein thecontrol module 106 converts the PPG signals to the frequency domainusing, for example, Fourier transform, wavelet analysis or otheralgorithms The control module 106 then filters the red light signal andthe infrared light signal with the filtering parameter so as torespectively generate a filtered red light signal and a filteredinfrared light signal. In one embodiment, the filtered red light signalis obtained by converting signal components at the basic frequency of afrequency domain red light signal (e.g. FIG. 2A) back to time domain,and the filtered infrared light signal is obtained by converting signalcomponents at the basic frequency of a frequency domain infrared lightsignal (e.g. FIG. 2A) back to the time domain.

The control module 106 may calculate the biometric characteristicaccording to at least one of the green light signal, the filtered redlight signal and the filtered infrared light signal. In one embodiment,the heart rate and the second derivative of photoplethysmogram areobtained according to one of the green light signal, the filtered redlight signal and the filtered infrared light signal; and the bloodoxygenation is obtained according to the filtered red light signal andthe filtered infrared light signal.

It should be mentioned that when the biometric detection module 1 isattached to other devices, e.g. an earphone, a part of functions of thecontrol module 106 may be performed by a processor of said devices. Forexample in some embodiments, the biometric detection module 1 detectsPPG signals, but the processing and filtering of the PPG signals and thecalculation of the biometric characteristic may be performed by anexternal processor.

Referring to FIGS. 3A, 3B and 4, FIGS. 3A and 3B are schematic diagramsof a biometric detection module 1 applied to glasses and FIG. 4 is aschematic diagram of wearing the glasses to which the biometricdetection module 1 is applied. Herein, the biometric detection module 1is attached to an eyeglass temple 3 and configured to detect at leastone biometric characteristic from a skin region behind ear S (as FIG. 4)corresponding to the temporal bone. In some embodiments, the biometricdetection module 1 includes a joint portion 130 and a detection unit 10,wherein as mentioned above the detection unit 10 includes a light sourcemodule 101, a detection region 103A and a control module 106, and has adetection surface Sd configured to be attached to the skin region behindear S. That is, said skin surface S herein is referred to a skin regionbehind ear. The joint portion 130 is configured to combine with theeyeglass temple 3. In some embodiments, the biometric detection module 1is fixed on the eyeglass temple 3 through the joint portion 130. Inother embodiments, the biometric detection module 1 is attachable anddetachable from the eyeglass temple 3 through the joint portion 130.

In addition, for facilitating the position adjustment of the biometricdetection module 1 to allow the detection surface Sd thereof to beaccurately attached to the skin region behind ear S, the biometricdetection module 1 further includes an adjustment portion 131 (as FIG.3B) connected between the joint portion 130 and the detection unit 10for adjusting a position of the detection unit 10, wherein theadjustment portion 131 is made of soft material which deforms under anexternal force and keeps its shape without the external force. Inaddition, the biometric detection module 1 may be formed as a signalbranch as shown in FIG. 3A or formed with a plurality of branches asshown in FIG. 3B, wherein different branches are used to disposedifferent components. For example, in FIG. 3A a power module and adetection unit are disposed at the same branch, but in FIG. 3B the powermodule 109 and the detection unit 10 are disposed at different branches.

In addition, when the biometric detection module 1 is attached toglasses with the display function, e.g. including an LCOS display, theglasses may show the biometric characteristic detected by the biometricdetection module 1 so as to form an eyeglass module capable of detectingbiometric characteristics.

Referring to FIG. 5, in another embodiment the biometric detectionmodule 1 is configured to detect at least one biometric characteristicfrom a skin region in concha S. Herein, the biometric detection module 1includes a main body 150 and a protrusion portion 151 protruding outwardfrom the main body 150 to be put in the concha. The detection unit isdisposed at the protrusion portion 151 and has a detection surface Sdconfigured to be attached to the skin region in concha S. That is,herein said skin surface S is a skin region in concha. In addition, theindication unit 108 and the power module 109 are disposed at the mainbody 150. For example, the indication unit 108 is a display device or aspeaker module for showing the biometric characteristic detected by thebiometric detection module 1 through images or audio. In addition, inthis embodiment the detection unit also includes a light source module101, a detection region 103A and a control module 106 whose functionsare described above and thus details thereof are not repeated herein.

In one embodiment, the biometric detection module 1 is attached to anearphone device, e.g. a Bluetooth earphone. It should be mentioned thatalthough in FIG. 5 the biometric detection module 1 is shown to have anearphone shape, when the biometric detection module 1 is arranged asindividual element without being attached to the earphone, it may haveother shapes without being limited to that shown in FIG. 5. In addition,for facilitating the mounting, the biometric detection module 1 mayinclude other structure(s) configured to be mounted on the outer ear orthe head without particular limitations.

FIG. 6 shows a detection unit of a thin biometric detection moduleaccording to one embodiment of the present disclosure, which includes atleast one light source module 101, a substrate 102, a plurality ofdetection pixels 103 and a plurality of contact points 105, wherein thedetection pixels 103 form an optical semiconductor detection region103A, which has a thin semiconductor structure 104 (further illustratedin FIGS. 9A and 9B). The contact points 105 are configured toelectrically connect the optical semiconductor detection region 103A tothe substrate 102 for being controlled by a control module 106 (as shownin FIG. 1A), wherein the detection pixels 103 may be arranged in a chip201 and the contact points 105 are served as outward electrical contactsof the chip 201. The light source module 101 is also electricallyconnected to the substrate 102, and the control module 106 is configuredto control the light source module 101 to illuminate the skin surface Ssuch that the emitted light may enter body tissues (e.g. the above skinregion behind ear or in concha) of a user. Meanwhile, the control module106 is also configured to control the detection pixels 103 to detectlight transmitting out from the body tissues. As vessels and blood inthe body tissues have different optical properties, by arrangingspecific light source module 101 the biometric characteristic may beidentified according to the optical images detected by the detectionpixels 103.

More specifically, the control module 106 may be integrated in the chip201 or disposed on the substrate 102 (on the same or different surfacesof the substrate 102 with respect to the chip 201) and configured tocontrol the light source module 101 and the optical semiconductordetection region 103A. The substrate 102 has a substrate surface 102S onwhich the chip 201 and the light source module 101 are disposed. In thisembodiment, in order to effectively reduce the total size, a relativedistance between the chip 201 and the light source module 101 ispreferably smaller than 8 millimeters.

In some embodiments, the contact points 105 may be the lead framestructure. In other embodiments, the contact points 105 may be bumps,the ball grid array or wire leads, but not limited thereto.

In some embodiments, an area of the detection region 103A is larger than25 mm². The optical semiconductor detection region may successivelycapture images at a frame rate higher than hundreds of frames persecond. For example, the control module 106 may control the opticalsemiconductor detection region 103A to capture optical images at a framerate higher than 300 frames per second and control the light sourcemodule 101 to emit light corresponding to the image capturing.

FIG. 7 is an upper view of the optical semiconductor detection region103A according to one embodiment of the present disclosure. In detectingbiometric characteristics, e.g. the blood oxygenation, the heart rate(pulse) and the blood pressure, as the skin surface S does not have fastrelative movement with respect to the detection surface Sd, the size ofthe detection region 103A does not obviously affect the detected result.FIG. 7 shows the detection region 103A as a rectangular type, and aratio of the transverse and longitudinal widths may be between 0.5 and2. Accordingly, no matter which of the biometric characteristics such asthe vein texture, blood oxygenation, pulse, blood pressure or secondderivative of photoplethysmogram of a user is to be detected, a useronly needs to attach the detection region 103A to the skin surface S. Anarea of the detection region 103A is at least larger than 25 mm².

FIGS. 8A and 8B are upper views of a thin biometric detection moduleaccording to some embodiments of the present disclosure, which show thearrangement of the light source and the application using a plurality oflight sources. In FIG. 8A, the light source module 101 is shown to bearranged at one side of a plurality of detection pixels 103 andelectrically connected to the substrate 102. It should be noted that inthis embodiment, although the light source module 101 is arranged at oneside of the detection pixels 103, as the light may penetrate into thebody tissues of the user, the position of the light source module doesnot affect the direction of the detection unit as long as the skinsurface is continuously illuminated by the light source module duringthe detection process.

In FIG. 8B, three different light sources 101 a, 101 b and 101 c areshown. In this embodiment, the term “different light sources” isreferred to the light sources emitting light of different wavelengths.As different components in the body tissues have different opticalresponses toward different light wavelengths, e.g. having differentabsorptions, by detecting different light sources the biometriccharacteristic associated with the light wavelengths may be derived andthe correction may be performed according to the detected imagesassociated with different light sources so as to obtain correct detectedresults. For example, the oxygen component in the blood has differentabsorptions associated with different light colors, and thus bydetecting the energy of different light colors the blood oxygenation maybe derived. In other words, the thin biometric detection moduleaccording to the embodiment of the present disclosure may include threelight sources 101 a, 101 b and 101 c respectively emitting light ofdifferent wavelengths, e.g. red light, infrared light and green light.And the optical semiconductor detection region 103A may include threetypes of detection pixels configured to respectively detect differentlight wavelengths emitted from the light sources.

For example, if the blood oxygenation is to be detected, two lightwavelengths close to the absorption wavelength 805 nm of HbO₂ and Hb maybe selected, e.g. about 660 nm and 940 nm. Or the light wavelengthbetween 730 nm and 810 nm or between 735 nm and 895 nm may be selected.The blood oxygenation may be derived according to the difference oflight absorption of blood between the two light wavelengths. Thewavelength of the green light is selected to be within the green lightspectrum without particular limitations. The related detectiontechnology is well known to the art and thus details thereof are notdescribed herein.

According to FIGS. 8A and 8B, it is known that a plurality of lightsources may be adopted in the present disclosure and is not limited touse only a single light source or two light sources. Furthermore,according to the biometric characteristic to be detected, differentdetection pixels may be arranged corresponding to more light sources,and the position of the light sources does not have particularlimitations. In the thin structure, the biometric detection module ofthe present disclosure may be applied to detect various biometriccharacteristics. Different light sources may also be adopted in order todetect biometric characteristics. If it is desired to acquire uniformimages, identical light sources may be arranged at both sides of samedetection regions such that light may enter the body tissues from twosides of the same detection regions.

FIGS. 9A and 9B are cross-sectional views of the optical semiconductordetection region according to some embodiments of the presentdisclosure, which are partial schematic diagrams of the thinsemiconductor structure 104. FIG. 9A is an embodiment in which a planarlayer 203 also has the abrasion-proof ability. For example, the planarlayer 203 made of polyimide material may have enough abrasion-proofability to be adapted to the present disclosure. That is, the planarlayer 203 is also served as the abrasion-proof layer herein. The planarlayer 203 is formed on the top of the chip structure 201 and on the chipsurface 201S to overlay the optical semiconductor detection region forprotecting the semiconductor structure 104. As the top of the chipstructure 201 may have many convexes and concaves (as shown in thefigure) after the metal layer and the electrode are formed thereon dueto the semiconductor layout, the non-uniform has a negative effect tothe optical detection and a weaker weather-proof ability. Accordingly,the planar layer 203 is formed on the top to allow the thinsemiconductor structure 104 to have a flat surface to be suitable to thepresent disclosure. In the present disclosure, as the thin semiconductorstructure 104 is exposed to air and directly in contact with the user'sbody frequently, a better abrasion-proof ability is required. In thesemiconductor manufacturing technology nowadays, the polyimide-basedmaterial may be selected as the abrasion-proof material. Meanwhile, theplanar layer 203 is preferably transparent to visible or invisible lightaccording to the selection of the light source. In addition, theabrasion-proof material may be glass material or the like. For example,the abrasion-proof layer is a glass layer.

It should be noted that in order to reduce the diffusion of light whenpassing through the planar layer 203 to blur the image, preferably adistance from the surface of the semiconductor structure 104 to thesurface of the chip structure 201, i.e. the thickness of the planarlayer 203 herein, is limited to be smaller than 100 micrometers. Thatis, a distance from the chip surface 201S to an upper surface of theplanar layer 203 (i.e. the abrasion-proof layer) is preferably smallerthan 100 micrometers. When detecting the biometric characteristic, theupper surface of the planar layer 203 is configured as the detectionsurface Sd to be directly in contact with a skin surface S such thatlight emitted from the light source module 101 directly illuminates theskin surface S and sequentially passes through the body tissues and theplanar layer 203 to be detected by the optical semiconductor detectionregion. In one embodiment, a distance between an emission surface of thelight source module 101 and the substrate surface 102S is identical to adistance between the upper surface of the planar surface 203 and thesubstrate surface 102S. That is, when an emission surface of the lightsource module 101 and an upper surface of the planar surface 203 have anidentical height, the light emitted by the light source module 101 mayefficiently pass through the skin surface to enter the part of humanbody and be detected by the optical semiconductor detection region.

The difference between FIG. 9B and FIG. 9A is that the planar layer 203in FIG. 9B does not have enough abrasion-proof ability, and thus anotherabrasion-proof layer 205 is formed upon the planar layer 203. Similarly,in order to reduce the diffusion of light when passing through theplanar layer 203 and the abrasion-proof layer 205, in this embodiment atotal thickness of the planar layer 203 and the abrasion-proof layer 205is preferably limited to be smaller than 100 micrometers. In thisembodiment, the planar layer 203 may be any material without consideringthe abrasion-proof ability thereof and the abrasion-proof layer 205 maybe made of polyimide-based abrasion-proof material. In addition, theabrasion-proof material may be glass material or the like. For example,the abrasion-proof layer is a glass layer.

In some embodiments, it is possible to arrange a plurality of detectionregions, e.g. arranging a plurality of linear detection regions along apredetermined direction or inserting light sources between a pluralityof linear detection regions. For example, the linear opticalsemiconductor detection regions may be arranged adjacent to each other,or the linear optical semiconductor detection regions and a plurality oflight sources may be arranged alternatively so as to obtain a betteroptical imaging. As the detection principle is not changed, detailsthereof are not described herein.

Said substrate 102 is configured to electrically connect the lightsource module 101 and the detection pixels 103 and to allow the lightsource module to emit light to enter the body tissues, and thus thesubstrate may be a flexible soft substrate or a hard substrate made ofhard material without particular limitations.

In the embodiment of a thin type structure, the optical semiconductordetection region may be directly attached to the skin surface of a userwithout other optical mechanism(s) to perform the image scaling and thelight propagation. And thin and durable features thereof are suitable tobe applied to head accessories or ear accessories, e.g., the glasses andearphones.

In some embodiments, according to the adopted light source, differentlight filters may be formed during manufacturing the detection pixels toallow the desired light to pass through the filter and be received bythe detection pixels. The filters may be formed in conjunction with thesemiconductor manufacturing process on the detection pixels using theconventional technology or formed on the detection pixels after thedetection pixels are manufactured. In addition, by mixing the filteringmaterial in the protection layer and/or the planar layer, the protectionlayer and/or the planar layer may have the optical filtering function.That is, in the embodiment of the present disclosure, said differentdetection pixels may be referred to the detection pixels with differentlight filters but not referred to the detection pixels with differentstructures.

It is appreciated that in order to reduce the size, the biometricdetection module 1 is illustrated by the embodiment shown in FIG. 6, butnot limited thereto. In some embodiments, other optical mechanism(s) maybe disposed between the light source module 101 and the skin surface Sto be detected or between the detection region 103A and the skin surfaceS to be detected according to different applications.

Referring to FIG. 10, it is a flow chart of a biometric detection methodof a biometric detection module according to one embodiment of thepresent disclosure, which includes the steps of: emitting, using a lightsource module, green light, red light and infrared light in a timedivision manner to a skin surface (Step S₄₁); detecting, using asemiconductor detection region, penetrating light illuminating the skinsurface and passing through body tissues to correspondingly generate agreen light signal, a red light signal and an infrared light signal(Step S₄₂); determining a filtering parameter according to the greenlight signal (Step S₄₃); filtering the red light signal and the infraredlight signal with the filtering parameter to generate a filtered redlight signal and a filtered infrared light signal (Step S₄₄); andcalculating at least one biometric characteristic according to at leastone of the green light signal, the filtered red light signal and thefiltered infrared light signal (Step S₄₅).

Referring to FIGS. 1A-2B, 6 and 10 together, details of the presentembodiment are illustrated hereinafter.

Steps S₄₁-S₄₂: The light control module 106 controls the light sourcemodule 101 to emit green light, red light and infrared light in a timedivision manner to illuminate a skin surface S, and controls thedetection region 103A to detect penetrating light emitted from the lightsource module 101 for illuminating the skin surface S and passingthrough body tissues corresponding to the light emission of the lightsource module 101 (as FIG. 1B) so as to correspondingly generate a greenlight signal, a red light signal and an infrared light signal, whereinthe green light signal, the red light signal and the infrared lightsignal are PPG signals. The skin surface S is determined according tothe application of the biometric detection module 1.

Step S₄₃: The control unit 103 converts, using the built-in algorithm,the green light signal to frequency domain so as to generate a frequencydomain green light signal (e.g. FIG. 2B), and determines a basicfrequency of the frequency domain green light signal to be served as afiltering parameter, e.g. frequency components at 1 Hz shown in FIG. 2B.

Step S₄₄: The control module 106 also converts the red light signal andthe infrared light signal to the frequency domain to generate afrequency domain red light signal and a frequency domain infrared lightsignal as shown in FIG. 2A, and as the noise level is too high, the mainfrequency component is not identifiable. The control module 106 thenconverts the signal components associated with the basic frequency (e.g.1 Hz) of the frequency domain red light signal and the frequency domaininfrared light signal back to time domain according to the filteringparameter determined in the Step S₄₃ so as to generate a filtered redlight signal and a filtered infrared light signal, wherein the filteredred light signal and the filtered infrared light signal are filtered PPGsignals.

Step S₄₅: Finally, as most of movement noises in the filtered red lightsignal and the filtered infrared light signal are removed, the controlmodule 106 may calculate the biometric characteristic accordingly,wherein the method of calculating the blood oxygenation according to thered light PPG signal and the infrared light PPG signal is known to theart and thus details thereof are not described herein. In addition, thesecond derivative of photoplethysmogram is obtainable according to asingle PPG signal, and as SPO₂ has a higher absorption of the greenlight, the control module 106 may obtain the second derivative ofphotoplethysmogram and the heart rate according to one of the greenlight signal, the filtered red light signal and the filtered infraredlight signal.

As mentioned above, the conventional biometric detection module maygenerate larger noises when detecting a moving skin surface, and thuscorrect biometric characteristics are difficult to be detected.Therefore, the present disclose further provides a biometric detectionmodule (FIGS. 1A and 6) and a biometric detection method thereof (FIG.10) that determine a filtering parameter according to a green lightsignal for removing noises in a red light signal and an infrared lightsignal thereby improving the detection accuracy. In addition, due to itsthin structure, the biometric detection module of the present disclosureis adaptable to various head accessories.

Although the disclosure has been explained in relation to its preferredembodiment, it is not used to limit the disclosure. It is to beunderstood that many other possible modifications and variations can bemade by those skilled in the art without departing from the spirit andscope of the disclosure as hereinafter claimed.

What is claimed is:
 1. A biometric detection device, configured todetect at least one biometric characteristic from a skin region in aconcha, the biometric detection device comprising: a biometric detectionmodule having a detection unit, the detection unit comprising: a lightsource module configured to emit green light, red light and infraredlight in a time division manner to illuminate the skin region; adetection region configured to detect penetrating light emitted from thelight source module for illuminating the skin region and passing throughbody tissues to correspondingly generate a green light signal, a redlight signal and an infrared light signal; and an abrasion-proof layercovering the detection region and having an upper surface as a detectionsurface, wherein a thickness of the abrasion-proof layer is smaller than100 micrometers, and the upper surface is configured to be in contactwith the skin region when detecting the biometric characteristic suchthat the light emitted from the light source module illuminates the skinregion and sequentially passes through the body tissues and theabrasion-proof layer to be detected by the detection region; and anearphone having a processor, the processor is configured to convert thegreen light signal to frequency domain to determine a filteringparameter according to a frequency domain green light signal,respectively convert the red light signal and the infrared light signalto a frequency domain red light signal and a frequency domain infraredlight signal, filter the frequency domain red light signal and thefrequency domain infrared light signal using the filtering parameterdetermined from the frequency domain green light signal, to obtain afiltered red light signal and a filtered infrared light signal, andcalculate the biometric characteristic according to at least one of thegreen light signal, the filtered red light signal and the filteredinfrared light signal.
 2. The biometric detection device as claimed inclaim 1, further comprising: a main body; a protrusion portionprotruding outward from the main body and configured to be put in theconcha; and an indication unit disposed in the main body and configuredto show the biometric characteristic, wherein the detection unit is atthe protrusion portion, and the detection surface is configured to beattached to the skin region in the concha.
 3. The biometric detectiondevice as claimed in claim 1, wherein the at least one biometriccharacteristic comprises a heart rate, a blood oxygenation and a secondderivative of photoplethysmogram.
 4. The biometric detection device asclaimed in claim 3, wherein the processor of the earphone is configuredto calculate the heart rate and the second derivative ofphotoplethysmogram according to one of the green light signal, thefiltered red light signal and the filtered infrared light signal, andcalculate the blood oxygenation according to the filtered red lightsignal and the filtered infrared light signal.
 5. The biometricdetection device as claimed in claim 1, wherein the filtering parameteris a basic frequency of the frequency domain green light signal.
 6. Thebiometric detection device as claimed in claim 5, wherein the processorof the earphone is configured to obtain the filtered red light signal byconverting signal components at the basic frequency of the frequencydomain red light signal back to time domain, and obtain the filteredinfrared light signal by converting signal components at the basicfrequency of the frequency domain infrared light signal back to the timedomain.
 7. The biometric detection device as claimed in claim 1, whereinthe detection region comprises photodiodes respectively configured todetect the red light, the infrared light and the green light.
 8. Abiometric detection module, configured to detect at least one biometriccharacteristic from a skin region, the biometric detection modulecomprising: a light source module configured to emit green light, redlight and infrared light in a time division manner to illuminate theskin region; a detection region configured to detect penetrating lightemitted from the light source module for illuminating the skin regionand passing through body tissues to correspondingly generate a greenlight signal, a red light signal and an infrared light signal; a controlmodule configured to control the light source module to emit light,determine a filtering parameter according to the green light signal toaccordingly filter the red light signal and the infrared light signal,and calculate the biometric characteristic according to at least one ofthe green light signal, the filtered red light signal and the filteredinfrared light signal; and an abrasion-proof layer covering thedetection region and having an upper surface as a detection surface,wherein a thickness of the abrasion-proof layer is smaller than 100micrometers, and the upper surface is configured to be in contact withthe skin region when detecting the biometric characteristic such thatthe light emitted from the light source module illuminates the skinregion and sequentially passes through the body tissues and theabrasion-proof layer to be detected by the detection region.
 9. Thebiometric detection module as claimed in claim 8, wherein the at leastone biometric characteristic comprises a heart rate, a blood oxygenationand a second derivative of photoplethysmogram.
 10. The biometricdetection module as claimed in claim 9, wherein the control module isconfigured to calculate the heart rate and the second derivative ofphotoplethysmogram according to one of the green light signal, thefiltered red light signal and the filtered infrared light signal, andcalculate the blood oxygenation according to the filtered red lightsignal and the filtered infrared light signal.
 11. The biometricdetection module as claimed in claim 8, wherein the control module isconfigured to convert the green light signal to a frequency domain greenlight signal and determine a basic frequency of the frequency domaingreen light signal as the filtering parameter.
 12. The biometricdetection module as claimed in claim 11, wherein the control module isfurther configured to obtain the filtered red light signal by convertingsignal components at the basic frequency of a frequency domain red lightsignal back to time domain, and obtain the filtered infrared lightsignal by converting signal components at the basic frequency of afrequency domain infrared light signal back to the time domain.
 13. Thebiometric detection module as claimed in claim 8, wherein the detectionregion comprises three kinds of detection pixels respectively configuredto detect the red light, the infrared light and the green light.
 14. Abiometric detection device, configured to detect at least one biometriccharacteristic from a skin region, the biometric detection devicecomprising: a biometric detection module, comprising: a light sourcemodule configured to emit green light, red light and infrared light in atime division manner to illuminate the skin region; a detection regionconfigured to detect penetrating light emitted from the light sourcemodule for illuminating the skin region and passing through body tissuesto correspondingly generate a green light signal, a red light signal andan infrared light signal; and an abrasion-proof layer covering thedetection region and having an upper surface as a detection surface,wherein a thickness of the abrasion-proof layer is smaller than 100micrometers, and the upper surface is configured to be in contact withthe skin region when detecting the biometric characteristic such thatthe light emitted from the light source module illuminates the skinregion and sequentially passes through the body tissues and theabrasion-proof layer to be detected by the detection region; and adevice having a processor, the biometric detection module being attachedto the device and the processor being configured to determine afiltering parameter according to the green light signal to accordinglyfilter the red light signal and the infrared light signal, and calculatethe biometric characteristic according to at least one of the greenlight signal, the filtered red light signal and the filtered infraredlight signal.
 15. The biometric detection device as claimed in claim 14,wherein the at least one biometric characteristic comprises a heartrate, a blood oxygenation and a second derivative of photoplethysmogram.16. The biometric detection device as claimed in claim 15, wherein theprocessor of the device is configured to calculate the heart rate andthe second derivative of photoplethysmogram according to one of thegreen light signal, the filtered red light signal and the filteredinfrared light signal, and calculate the blood oxygenation according tothe filtered red light signal and the filtered infrared light signal.17. The biometric detection device as claimed in claim 14, wherein theprocessor of the device is configured to convert the green light signalto a frequency domain green light signal and determine a basic frequencyof the frequency domain green light signal as the filtering parameter.18. The biometric detection device as claimed in claim 17, wherein theprocessor of the device is further configured to obtain the filtered redlight signal by converting signal components at the basic frequency of afrequency domain red light signal back to time domain, and obtain thefiltered infrared light signal by converting signal components at thebasic frequency of a frequency domain infrared light signal back to thetime domain.
 19. The biometric detection device as claimed in claim 14,wherein the detection region comprises three kinds of detection pixelsrespectively configured to detect the red light, the infrared light andthe green light.